1. Field of the Invention
The present invention relates to a battery having a positive electrode, a negative electrode and an electrolyte, more particularly, to a battery having the electrolyte containing a polymer compound synthesized by polymerization.
2. Description of the Related Art
Recently, accompanying by progress of electronics technique, a number of potable electronic equipment such as a camcorder (video tape recorder), a cellular phone and a portable computer has been popularized and advanced more miniaturization and lightning. Then, as a portable electronic source employed by the portable electronic equipment, a battery, especially, a secondary battery has been developed. Among the secondary batteries, a lithium ion secondary battery is expected to realize high energy density. Specifically, the lithium ion secondary battery excellent in flexibility with a thin foldable shape has been developed.
The battery excellent in flexibility employs a solid electrolyte without fear of leakage. As the solid electrolyte, for instance, a gel electrolyte where a polymer compound maintains a plasticizer containing an electrolyte salt, or a polymer solid electrolyte where the electrolyte salt is dissipated in the polymer compound is noteworthy. There are many reports on the gel electrolyte or polymer solid electrolyte. For example, the above-mentioned electrolytes can be produced by a simple method such that a solution containing a monomer is polymerized in order to be a gel or solid state.
Take the battery employing such electrolytes for instance, the electrolyte is fabricated by polymerizing the monomer after the positive electrode and the negative electrode are laminated with the separator in-between, then a solution containing the monomer is impregnated in the separator, or after the solution containing the monomer is applied on the positive electrode or the negative electrode.